I will be taking in a friends dogs for a week while she is visiting her BF here, but she cannot have her dog in his apartment, so we have agreed to take him in. The dog has SA, I've never dealt with a dog with that issue, so does anyone have any tips for me to make his stay as comfortable as possible?

Tire them out - physically and mentally. Take them for a run, go play fetch, do a training session, etc. Keep them busy - stuffed Kongs, bully sticks, kibble-toys, whatever.

This. Kimma could care less if Bubbles and Pen were here - she actually acts the same if she's alone or not (I've tried it multiple ways LOL). She doesn't have severe SA, but training helps TONS. She could run and play all day, but if her brain is still going, she's a mess when I leave.

At my work with SA dogs exhausting them helps and keeping them busy helps. Also for the dog friendly dogs having a friend helps.

Yes this. Especially working them mentally as well and physically and tapping any natural drives they might have.

I actually can't leave Scout alone without Lily there. I had her to where I could, but she relapsed bigtime and I have no choice but manage it by doing EVERYTHING with them together. Scout does get one on one time, but not being able to have that with Lily right now is driving me nuts.

DAP does help Scout a bit and you might do that since it'll be a new environment for the the dog.

Keeping to the dogs accustomed schedule as much as possible would also be good.